Russel bodies are seen in?

Ans. is 'a' i.e., Multiple Myeloma o Russell bodies are large homogenous eosinophilic inclusions formed by hugely distended endoplasmic reticulum of plasma cells. It is a characteristic feature of multiple myeloma,o In multiple myeloma, plasma cells can infiltrate the bone marrow diffusely or may be present in sheet like masses that completely replace normal elements. Plasma cells may be normal plasma cells but mostly they are atypical plasma cells (variants of plasma cell) produced by intracellular accumulation of intact or partially degraded immunoglobulins. These atypical plasma cells are : (i) Flame cells, and (ii) MOTT cells. Intracellular inclusions are Russel bodies cytoplasmic), Dutcher bodies (nuclear), crystalline rods and fibrils.Also remembero Electrophoresis of serum shows M band (monoclonal band) of immunoglobulin, most commonly of IgG.o Urine shows Bence-Jones protein (light chain component of Immunoglobulin).o Serum B2-microglobulin is increased and is the most important prognostic factor. There is increased serum uric acid and urea.o Monoclonal light chain may be detected both in serum and urine.